1. Field of the Invention
The invention relates to a steam condenser for on-floor arrangement with a steam turbine,
in which the steam is condensed on tubes through which cooling water flows and which are combined in separate sectional banks, for which purpose the sectional banks are horizontally directed in their longitudinal extent and a plurality of such sectional banks are arranged one above the other in the vertical, PA1 the tubes of a bank arranged in rows enclosing a hollow space in which a cooler for the non-condensable gases is arranged, and the mixture of non-condensable gases and steam which collects in the hollow space of the sectional bank being drawn off by the cooler, PA1 and the hollow space being connected to a compensating lane in the interior of the bank, which compensating lane ensures that the steam, enriched with inert gas, from the core of the front and the rear half of the bank is fed to the air cooler.
2. Discussion of Background
EP-A 0 384 200 discloses such a steam condenser. The condenser tubes are arranged in a plurality of sectional banks in a condenser casing. The steam flows through an exhaust-steam connection into the condenser casing and is distributed in the space by flow passages. The latter narrow in the general direction of the flow in such a way that an optimum pressure gradient is produced. The free inflow of the steam to the outer tubes of the sectional banks is ensured. The steam then flows through the banks with a small resistance due to the small depth of the tube rows. In order to be able to fulfill the condition of the steam velocity to be kept constant in the inflow passages, the sectional banks in the condenser are arranged one above the other in such a way that suitable flow passages are obtained between them. Furthermore, the tubes in the rows following one after the other form a wall which is closed upon itself and is preferably of identical thickness throughout.
The steam-side pressure drop over the bank is approximately constant as a result of the intentional realization of the reduction in pressure in the lanes, through which flow occurs, at the level of the air cooler on both sides of the respective bank. This results in a homogeneous pressure gradient in the direction of the cooler. Thorough flushing of steam through the bank is achieved by this measure. After passing through the maximum, velocity, the steam in the lanes is decelerated down to zero with recovery of pressure at the level of the condensate receiver. This causes an increase in the saturation temperature of the steam and thus a regeneration of the condensate undercooling which has taken place and of the oxygen concentration in the condensate. In addition, owing to the fact that the retention takes place only at the lower bank end due to the flow guidance selected, accumulations of non-condensable gases in the bank lanes themselves are avoided.
This known condenser has the advantage that, due to the more open arrangement of the sectional banks, all peripheral tubes of a sectional bank are readily fed with steam without a noticeable pressure loss. On the other hand, the requirement for an at least approximately uniform "wall thickness" of the tubed sectional bank around the hollow space results in a relatively large overall height of the sectional bank in its longitudinal extent. The excellent suitability of this concept for steam condensers of power station plants in which the condenser and the turbine are located at approximately the same level of the foundation of the power house results from the horizontal orientation of the sectional banks. In such cases, the condenser may be arranged coaxially to the turbine shaft or laterally along the turbine. Further advantages may be seen in the simple and quick production of the foundation as well as in short commissioning times. In particular, it is possible to dispense with the previous expansion members and to attach the condenser directly to the exhaust-gas casing of the turbine and to support the condenser by means of simple sliding shoes.